Transformer



Feb. 8, 1927.l

A. H.' WEGNER, JRV

TRANSFORMER Filed Dec. 12, 1925 Patented Feb. 8, 1927.

UNITED STATES 1,616,646 PATENT OFFICE.

ABTHUR'HfWEGNEB, JR., OF WASHINGTON, DISTRICT OF COLUMBIA.

. TBANSFOBMER.

Application led December .12, 1925. Serial No. 75,048.

around the transformer and thus eliminate type.

undesired coupling with other units of the receivinglsystem; and operative to provide a coupling for a radio apparatus tending to stabilize the action of the apparatus and to increase the range and signal strength.

Another object of the invention is to pro. vide an air core transformer operative to e-fliciently amplify signals received while providing a sharp tune and which may be constructed at a relative low cost.

Various other objects and advantages of the invention will be apparent from the description ofa referred form embodying the invention set orth hereinafter.

In the accompanying drawings, the invention is shown in its preferred form or forms in which Figure 1 is a sectional elevation of the preferred form of the air core transformer.

Fivure 2 is a sectional elevation of a modified form of the air core transformer.

Figure 3 is a top vview of the air core transformer.

Figure V4 is an elevated diagram of a wi reless receiving; or radio apparatus embodying the invention;

Referring to the drawings 1 represents the ordinary grounded aerial or antenna connectedl through an air core radio frequency transformer, 2, embodying the present invention, the antenna 1 being connected through the parallel primar windings 3 of the transformer, and groun ed as indicated at 4. 5 indicates arallel secondary windings of the trans ormer, the terminals of which may, if desired, be connected as usual directl with a detectorof an well known or example, the thermlonic detector 6. 'In the preferred form of circuit shown the secondar windings 5 are connected as usual throng va grid leak 7 in the grid circuit.

The plate circuit of the detector tube 6,

preferably connects through the phones 9, a positive potential being impressed upon the plate 10 of the detector tube' from a suitablev source indicated by the B battery. The

secondary windings 5 ofthe transformer 2 are preferably shunted by a tuning element such as a condenser 11. The filament cirv cuit comprises the usual A battery, fila- `rncnt 12 of the detector,-and the control resistance 13. l

The air core frequency transformer comprises a plurality of cylindrical shells made of vmaterial having insulating properties disposed' one within the other and so mounted;` as to permit an air space between the respective shells, each shell being provided Wi'th a primary winding or a secondary winding on its exterior surface or a secondary winding on its exterior surface and `a primary Winding on its interior surface,

the respective secondary or primary windings being connected Vin parallel.

The transformer 2 made in accordance with this invention comprises cylindrical shells or tubes 15, 16, and 17, which are suitably mounted one within the other and retained in spaced relation to each other by means of screws 18, lock Washers 19 and nuts 20. Shell 17 is provided with a primary winding 21 on its interior face and a secondary Winding 22 on its exterior face, shell 16 is provided with a primarywinding 23 on its' exterior face, and shell 15 is provided with a secondary winding 24 on its exterior face as clearly shown in Fig. 2.

It is to be noted that in this construction the secondary windings are connected-in parallel as .are also the primary windings.

In the preferred structure as shown in Fig. 1, shell or tube is provided with a secondary winding 24 on its exterior face and a primary Winding 25 on its interior face, shell 16 is provided with a secondary winding 26 on its exterior face and a primary winding 27 on its interior face, and shell 1.7 is provided witha secondary Winding 28 on its exterior face and a primary winding 29 on its interior face, all of the secondary windings being connected in parallel as are all the primary windings.

It is to be noted that the size and the length of the wire constituting the primary or secondary windings on each one of the tubes or shells is exactly the same irrespective of the circumference of the particular shell or tube. -In other words, the length of wire constituting the primary windings on each one of the plurality of tubes or shellsmust be precisely the saine as must also the length constituting' the secondary windings on each one of the plurality of shells.4 Any variation in the size or length of the Wire will cause the defeat of the desired results linherent to a transformer made in accordance with this invention.

This type of vtransformer is adapted for use in any of the well known type of radio or carrier frequency signalling systems, and

is particularly effective when usedl in association with the antenna and in place lof the transformers commonly used between the respective detector tubes, as in the case of` in theother and having a permanently maintained air space between the respective shells, the said shells carrylng primary or secondary windin on their respective faces', thev different windings being 'connected in parallel.

2. In a radio frequenc transformer, a plurality of coaxial shells isposed one with- 3. A radio frequenc transformer comprising a plurality of coaxial shells disposedy lone within the other and having a permanently maintained air space between the respective shells, each shell carrying a primary 'winding on its interior face and a'secondary winding on its exterior face, the different windings beingconnected in parallel.

4. A radio frequency transformer, comprisin a plurality ofcoaxial shellsV disposed one within the other and having a. perma-l nentlyvmaintained air space between the respective' shells, each shell 'carrying a. primarywindin on its interior face and a secondary win ing on its exterior face, the windings on the respective shells constitutingthe primary'or the secondary windings being of the same length, the'sa-id windings being connectedin parallel.

ARTHUR H. WEGNER, Jn 

